package org.yq.tools.encrypt;

import java.util.Date;
import java.util.Random;
import java.util.UUID;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.yq.tools.exception.EncryptException;

/**
 * AES对称加密
 * 
 * @author yuquan
 * @date 2023-5-2
 * @version 1.0
 */
public class AESUtil {

	public static String encrypt(String strKey, String strIn) throws Exception {
		SecretKeySpec skeySpec = getKey(strKey);
		Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
		IvParameterSpec iv = new IvParameterSpec("0102030405060708".getBytes());
		cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
		byte[] encrypted = cipher.doFinal(strIn.getBytes());
		return Base64.encode(encrypted);
	}

	public static String decrypt(String strKey, String strIn) throws Exception {
		SecretKeySpec skeySpec = getKey(strKey);
		Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
		IvParameterSpec iv = new IvParameterSpec("0102030405060708".getBytes());
		cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
		byte[] encrypted1 = Base64.decode(strIn);
		byte[] original = cipher.doFinal(encrypted1);
		String originalString = new String(original);
		return originalString;
	}

	private static SecretKeySpec getKey(String strKey) throws Exception {
		byte[] arrBTmp = strKey.getBytes();
		byte[] arrB = new byte[16]; // 创建一个空的16位字节数组（默认值为0）
		for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) {
			arrB[i] = arrBTmp[i];
		}
		SecretKeySpec skeySpec = new SecretKeySpec(arrB, "AES");
		return skeySpec;
	}

	public static String encrypt(String strIn) {

		String code = null;
		try {
			Random rand = new Random((new Date()).getTime());
			int num = rand.nextInt(10);
			String key = num + UUID.randomUUID().toString().replace("-", "").substring(0, num);
			code = AESUtil.encrypt(key, strIn);
			code = key + code;
		} catch (Exception e) {
			throw new EncryptException("encrypt error ", e);
		}
		return code;
	}

	public static String decrypt(String strIn) {
		String code = null;
		try {
			int num = Integer.valueOf(strIn.substring(0, 1));
			String key = strIn.substring(1, num + 1);
			key = num + key;
			strIn = strIn.substring(num + 1);
			code = AESUtil.decrypt(key, strIn);
		} catch (Exception e) {
			throw new EncryptException("encrypt error ", e);
		}
		return code;
	}
}
